Conservation Medicine & Zoonosis
So I came across the phrase ‘conservation medicine’ today. In a nut shell it’s a new and exciting take on medicine that combines the key issues in animal, human and ecosystem health, looking at and drawing links between each one. As a vet of the future this is big and exciting news for me as it provides an opportunity to dive in to the world of human medicine as well as that of fascinating ecosystems. It draws together each aspect of life on this planet meaning we can all work together to solve key issues. Here’s a link to Edinburgh Vet School’s conservation medicine programme for those of you who are interested:
http://www.ed.ac.uk/schools-departments/vet/studying/postgraduate/taught-programmes/conservation-medicine/about/background
A big issue in conservation and veterinary medicine is that of zoonotic disease. These are diseases spread from an animal to a human. Reverse zoonosis or ‘anthroponotic’ diseases are the opposite, so are transmitted from humans to animals. Here’s a little information on both:
Anthroponotic diseases: Humans can either pass on the same disease or a different form to the animal. These diseases are most often transmitted softy, as in ‘skin to skin’, as it’s not often you find infected humans inflicting bite wounds on animals. An example is a disease called chytridiomycosis which can be spread by humans to frogs due to a fungus on our hands.
Zoonosis: A recent survey states that of 1,415 pathogens known to infect humans, 61% were zoonotic. There’s a nice evolutionary explanation for this ( which is how I like it. I love when you can clearly and logically see how things came about through evolution). Basically prehistoric humans spent a lot of time in small, isolated groups of hunter-gatherers and were not often in contact with other such groups. This meant that diseases that were epidemic or pandemic, which depend on a constant ‘supply’ of humans who have not developed an immune response, had a tendency to kill off one of these groups and have nowhere else to go. This meant that as a result of natural selection, pathogens with the ability to stay alive in the host for long periods, or have a non-human reservoir in which to live, strived. They could live inside an animal and wait for the next group of humans to come along. These are known as chronic infections as they reoccur over time. Much of human development and evolution has been in relation to zoonotic, not epidemic, diseases, as these are the ones that reoccur and form a persistent threat.
There’s a huge list of zoonotic diseases so I’ve picked a two at random (okay, so the ones with cool names) to mention in more detail.
Sodoku (…Sorry. I’ve just returned from a month’s backpacking and my puzzle book was my saviour on long train journeys. This disease’s name drew me straight in!)- This zoonotic disease is mostly seen in Asia and is a form of Rat Bite Fever. The infections are acquired through rat bites or scratches and the incubation period is 4 to 28 days. The initial wound may seem slightly inflamed or ulcerated but heals as any other wound would. It’s the reappearing symptoms which show you have been infected. These include recurring fever and serious complications include hepatitis and meningitis. The symptoms can keep reoccurring for months or even years.
Cat Scratch Disease - This one is most commonly found in children following a scratch or bite from a cat (most commonly kittens). It causes symptoms such as decreased appetite and joint pain. The disease usually resolves spontaneously, with or without treatment, in one month.
More well-known zoonotic diseases include Lyme disease, Salmonella, Rabies and Ringworm. Those in the news recently are swine flu and bird flu.
Anyway that’s all for today. Hope you are all well, and feel free to drop me an ask! Whether it be a question or some information I’ve missed/ would find interesting, I appreciate every single one.